MDS

A lightweight FastMCP server that exposes read-only Cisco MDS NX-OS show commands as Model Context Protocol tools. Point it at one or many MDS switches and let an LLM client (VS Code, Claude, a LangChain agent, etc) inspect your SAN fabric in plain language.

• Read-only & safe — every tool maps to a show command over NX-API (JSON-RPC).
• Multi-switch — register as many switches as you want; clients pick one per call.
• Two transports — stdio or http.
• 63 tools spanning zoning, device-aliases, FLOGI/FCNS, VSANs, interfaces, port-channels, transceivers, counters, environment, logging, and inventory.
• Generative UI — in MCP-Apps-capable clients, the model can turn show output into live charts, tables, and dashboards on the fly.

Requirements

• Python 3.13+
• uv
• Cisco MDS switch(es) with NX-API enabled (feature nxapi)

Configuration

Switches are declared with indexed environment variables. Add more by repeating the block with the next number (gaps are tolerated):

Variable	Required	Default	Description
MCP_TRANSPORT		http	stdio or http
MCP_HOST		0.0.0.0	HTTP bind address
MCP_PORT		8000	HTTP bind port
MDS_<N>_HOST	✅	—	Switch IP or hostname
MDS_<N>_USERNAME	✅	—	NX-API username
MDS_<N>_PASSWORD	✅	—	NX-API password
MDS_<N>_NAME		the host	Friendly name used by the switch argument
MDS_<N>_PORT		8443	NX-API HTTPS port
MDS_<N>_VERIFY_SSL		false	Verify the TLS certificate

MDS_1_NAME=mds-fab-a
MDS_1_HOST=192.0.2.10
MDS_1_USERNAME=admin
MDS_1_PASSWORD=secret

MDS_2_NAME=mds-fab-b
MDS_2_HOST=192.0.2.11
MDS_2_USERNAME=admin
MDS_2_PASSWORD=secret

Copy .env.example to .env and fill it in. On startup the server reads this .env file, so you don't have to export the variables by hand. Variables set in the actual environment (shell, Docker, or an MCP client's env block) take precedence over .env.

Run

Install dependencies once, then start the server:

uv sync                 # create the virtualenv and install dependencies

uv run python main.py   # start the server (defaults to HTTP on http://localhost:8000/mcp)

To use stdio instead of HTTP, set MCP_TRANSPORT=stdio — either in .env (MCP_TRANSPORT=stdio) or inline for a single run:

MCP_TRANSPORT=stdio uv run python main.py

Docker / Podman

Build the image, then run it with your .env providing the switch credentials. The commands below use docker; replace it with podman if you prefer (the syntax is identical):

docker build -t mds-mcp .
docker run --rm -p 8000:8000 --env-file .env mds-mcp   # HTTP on http://localhost:8000/mcp

Using it from a client (Visual Studio Code)

Using Visual Studio Code here for the example, but any LLM client that supports MCP will work more or less the same way.

You register the server in a mcp.json file: .vscode/mcp.json for this workspace only, or your user mcp.json (Command Palette → MCP: Open User Configuration) to use it everywhere. Pick one of the two options below, paste it into that file, then open the Command Palette → MCP: List Servers → cisco-mds → Start.

Option A — HTTP

You run the server yourself; VS Code just connects to it.

1. Configure your switches in .env (see Configuration).
2. Start the server: uv run python main.py.
3. Add this to mcp.json:

{
  "servers": {
    "cisco-mds": { "type": "http", "url": "http://localhost:8000/mcp" }
  }
}

Option B — stdio

VS Code launches the process for you. Set cwd to where you cloned the repo so the server finds your .env. The env block below is optional — use it only to set or override variables without an .env file (remember it takes precedence over .env).

{
  "servers": {
    "cisco-mds": {
      "type": "stdio",
      "command": "uv",
      "args": ["run", "python", "main.py"],
      "cwd": "/path/to/mds-mcp",
      "env": {
        "MCP_TRANSPORT": "stdio",
        "MDS_1_HOST": "192.0.2.10",
        "MDS_1_USERNAME": "admin",
        "MDS_1_PASSWORD": "secret"
      }
    }
  }
}

Once started, open Copilot Chat and the cisco-mds tools become available to the model.

Usage

Ask the model questions in plain language about your SAN fabric. Examples:

• "List the configured switches and their software version."
• "Which zones are active in VSAN 20 on mds-fab-a?"
• "Show me the FLOGI database on both switches."
• "List all device aliases and tell me which ones aren't logged in right now."
• "Resolve pwwn 50:00:00:00:00:00:00:01 to a device alias and show its FCNS entry."
• "Are there any interfaces with CRC errors or link failures on mds-fab-b?"
• "Compare the transceiver Rx/Tx power on all fc interfaces and flag anything below -7 dBm."
• "Which ports are members of port-channel 220, and what's their negotiated speed?"
• "Show the traffic counters for interface fc1/3 — how much is it sending vs receiving?"
• "Which interfaces are seeing the most txwait or discarded frames on mds-fab-a?"
• "Summarize the VSAN membership across both fabrics."
• "Check the environment and module status — any failed fans, power supplies, or modules?"

Tool catalog

All tools are read-only.

Area	Tools
Discovery	list_switches
Zoning	show_zone, show_zone_active, show_zone_name, show_zone_vsan, show_zone_name_vsan, show_zone_status, show_zoneset, show_zoneset_active, show_zoneset_active_vsan, show_zoneset_name, show_zoneset_vsan, show_zoneset_name_vsan
Devices Aliases	show_device_alias_database, show_device_alias_name, show_device_alias_pwwn
System / Inventory	show_hardware, show_version, show_inventory, show_module, show_module_uptime, show_boot, show_switchname, show_cdp_neighbors, show_hosts, show_environment
Interfaces and Port-Channels (all)	show_interface_brief, show_interface_bbcredit, show_interface_transceiver, show_interface_transceiver_detail, show_interface_description, show_interface_mgmt, show_port_channel_summary, show_port_channel_usage
Interface detail (per-port)	show_running_config_interface_for, show_interface_for, show_interface_brief_for, show_interface_bbcredit_for, show_interface_transceiver_for, show_interface_transceiver_detail_for, show_interface_description_for
Flogi / Name Server / Login	show_flogi_database, show_flogi_database_for, show_flogi_database_vsan, show_fcns_database, show_fcns_database_vsan, show_fcns_database_detail
VSAN	show_vsan, show_vsan_id, show_vsan_usage, show_vsan_membership, show_vsan_membership_for
Interface Counters	show_interface_counters, show_interface_counters_brief, show_interface_counters_for, show_interface_counters_brief_for, show_interface_counters_detailed_for, show_interface_aggregate_counters_for
Sessions / Users	show_users, show_accounting_log
Logging	show_logging
Generative UI	generate_prefab_ui, search_prefab_components

Generative UI

The server registers FastMCP's GenerativeUI provider, which exposes two extra tools: generate_prefab_ui and search_prefab_components. In a client that supports MCP Apps, the model can take the raw JSON from any show tool and render it as an interactive Prefab view — bar/pie charts, sortable tables, KPI cards, and full dashboards — without any purpose-built UI tool. For example:

• "Query the interface brief on mds-fab-a and chart the ports per VSAN."
• "Build a dashboard of interface performance counters for mds-fab-b."
• "Show the FCNS database as a sortable table grouped by VSAN."

Clients without MCP-Apps support still get the underlying show data as JSON.

Disclaimer

A personal project, not affiliated with or endorsed by Cisco.